An evidence-based approach to human dermatomes.

The dermatome is a fundamental concept in human anatomy and of major importance in clinical practice. There are significant variations in current dermatome maps in standard anatomy texts. The aim of this study was to undertake a systematic literature review of the available evidence for the distribution of human dermatomes. Particular emphasis was placed on the technique of ascertainment, the location and extent of each dermatome, the number of subjects studied, and methodologic limitations. Our findings demonstrate that current dermatome maps are inaccurate and based on flawed studies. After selecting the best available evidence, a novel evidence-based dermatome map was constructed. This represents the most consistent tactile dermatomal areas for each spinal dorsal nerve root found in most individuals. In addition to highlighting the orderly arrangement, areas of consistency and clinical usefulness of dermatomes, their overlap and variability deserve greater emphasis. This review demonstrates the validity of an evidence-based approach to an anatomical concept.